Abstract

Laser Doppler anemometry is based on light scattered from small particles in a fluid. When measurements are made near a surface the reflections from the surface may decrease the SNR of the Doppler bursts. This paper discusses a method to separate scattered light from reflected light by means of circularly polarized light. The relations describing the scattering of circularly polarized light are given and scattering diagrams are calculated for various Mie parameters and refractive indices. It is shown which collection angles, particle diameters and refraction indices should be used in LDA to efficiently quench the reflections from surfaces.

© 1982 Optical Society of America

Effect of wall scattering on SNR in laser Doppler anemometry

H. Mishina, N. S. Vlachos, and J. H. Whitelaw
Appl. Opt. 18(14) 2480-2485 (1979)

Reflection suppression by polarization in backscatter LDA measurements near walls and in two-phase flows

J. Gardavský and Rolf Kleine
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